某大桥倾斜塔柱新浇混凝土模板侧压力测试与分析

The Test and Analysis of the Lateral Pressure of Freshly Poured Concrete on the Formwork for the Inclined Column of a Bridge Project

采用高精度振弦式压力盒对某桥斜塔现浇混凝土模板侧压力进行监测,得到了各个时间点模板侧压力沿高度方向的分布和各测试点模板侧压力随时间的变化规律。结果显示:随着浇筑高度增大,模板侧压力增加;从混凝土浇筑完成到初凝的时间段内,模板侧压力减小;初凝后混凝土内部温度升高导致模板侧压力再度增加,且其值远大于浇筑时有效压头引起的侧压力。研究成果可供倾斜混凝土塔柱施工和模板安全设计参考。

A high-precision vibrating string pressure box is used to monitor the lateral pressure of freshly poured concrete on the formwork for the inclined tower of a bridge project,with the distribution of the lateral pressure along the height at each time point and the variation of the lateral pressure of each test point with the time obtained.The results show that:the lateral pressure increases with the increase in the pouring height;the lateral pressure decreases in the period between the completion of pouring concrete and the initial setting of the poured concrete;after the initial setting of the concrete,the rise in the internal temperature of the concrete results again in the rise in the lateral pressure of the formwork,with its value far greater than the lateral pressure resulting from the effective head when concrete is poured.The results of our research may serve as a useful reference for the construction of inclined concrete tower columns and the safety design of formwork.